243 LS heads - fully assembled

I have a set of 243 casting number LS style cylinder heads for sale. They are stock and unmolested, in perfect condition. The heads are fully assembled with stock valves and valve springs and they are ready to drop on a motor today.

I need $500.

Call or text me at 918-3four6-87zero6

http://i.ebayimg.com/t/243-casting-L...Svw~~60_58.JPG

6.0 or 5.7 heads?

They were aluminum 5.3 heads. What engine size they came off of doesn't matter. All that matters is the year they were made. Some early ones had probs with the casting process or some shiz. These should be good.

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Originally Posted by AFSP1211

They were aluminum 5.3 heads. What engine size they came off of doesn't matter. All that matters is the year they were made. Some early ones had probs with the casting process or some shiz. These should be good.

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Yes yes yes. Thanks bud.

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Originally Posted by AFSP1211

They were aluminum 5.3 heads. What engine size they came off of doesn't matter. All that matters is the year they were made. Some early ones had probs with the casting process or some shiz. These should be good.

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Not totally true...if they came off an 6.0 ls2 and are stock they would have the sodium filled valves so yes it does matter.

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Originally Posted by bangbangskeetskeet

Not totally true...if they came off an 6.0 ls2 and are stock they would have the sodium filled valves so yes it does matter.

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He's talking about the casting, boss. But yes...

6.0, 5.3, 5.7 have diff combustion chamber sizes. If u put 6.0 heads on a 5.3 u will loose compression

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Originally Posted by bootlife

If u put 6.0 heads on a 5.3 u will loose compression

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Are you sure. Surely a larger cumbustion chamber wouldn't drop compression..... Bump for a good seller and thread crappers

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Originally Posted by bootlife

6.0, 5.3, 5.7 have diff combustion chamber sizes. If u put 6.0 heads on a 5.3 u will loose compression

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Not if they're all the same casting number. 799/243's are the same no matter what engine they come off of. 5.3, 5.7, 6.0 have all used 243/799 heads at some point, and they're all the same.

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Originally Posted by ecld_07

Are you sure. Surely a larger cumbustion chamber wouldn't drop compression..... Bump for a good seller and thread crappers

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Originally Posted by Frenchy

Not if they're all the same casting number. 799/243's are the same no matter what engine they come off of. 5.3, 5.7, 6.0 have all used 243/799 heads at some point, and they're all the same.

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Thanks guys...

There is a diff in combustion chamber size. If they were the same a 6.0 head that's running 9.1 compression would be way lower if u put it on a 4.8, that's y they say to mill the heads to up comp. if the heads were all the same based on casting numbers 6.0s would run cupped shaped pistons, and 4.8 would need domes to make up the diff in comp because of bore size. 5.7 heads on a 6.0 will give u a bump in compression. There chambers are set up for a smaller piston than the 6.0s. Call trick flow n ask bout a set of heads that are 9.1:1 compression, and they will ask wat ur putting them on. Combustion chamber and pistion, size and type play big rolls in compression. So lol what motor did ur heads come off of?

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Originally Posted by bootlife

There is a diff in combustion chamber size. If they were the same a 6.0 head that's running 9.1 compression would be way lower if u put it on a 4.8, that's y they say to mill the heads to up comp. if the heads were all the same based on casting numbers 6.0s would run cupped shaped pistons, and 4.8 would need domes to make up the diff in comp because of bore size. 5.7 heads on a 6.0 will give u a bump in compression. There chambers are set up for a smaller piston than the 6.0s. Call trick flow n ask bout a set of heads that are 9.1:1 compression, and they will ask wat ur putting them on. Combustion chamber and pistion, size and type play big rolls in compression. So lol what motor did ur heads come off of?

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An all aluminum 5.3 with FLAT TOP PISTONS

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Originally Posted by bootlife

There is a diff in combustion chamber size. If they were the same a 6.0 head that's running 9.1 compression would be way lower if u put it on a 4.8, that's y they say to mill the heads to up comp. if the heads were all the same based on casting numbers 6.0s would run cupped shaped pistons, and 4.8 would need domes to make up the diff in comp because of bore size. 5.7 heads on a 6.0 will give u a bump in compression. There chambers are set up for a smaller piston than the 6.0s. Call trick flow n ask bout a set of heads that are 9.1:1 compression, and they will ask wat ur putting them on. Combustion chamber and pistion, size and type play big rolls in compression. So lol what motor did ur heads come off of?

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I have never seen someone with both their foot in their mouth and their head up their ass. Congratulations.

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Originally Posted by Frenchy

Not if they're all the same casting number. 799/243's are the same no matter what engine they come off of. 5.3, 5.7, 6.0 have all used 243/799 heads at some point, and they're all the same.

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Like I said above the only difference would be if they came off a true LS2 from the car....then they would have the sodium filled valves. But other than that they are the exact same heads that come on the 4.8,5.3,and the 6.0 in all GM's cars and trucks.

The LS6 heads are the ones that had sodium longer valves
The LS2 heads had the same springs as the LS6 heads did but normal valves
5.3 HO motors had 243 or 799
53 trailblazers had 243
GenIV 4.8 and 5.3s have 243/799

all these heads have same chambers

difference was the pistons over the yrs for different models

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Originally Posted by bootlife

There is a diff in combustion chamber size. If they were the same a 6.0 head that's running 9.1 compression would be way lower if u put it on a 4.8, that's y they say to mill the heads to up comp. if the heads were all the same based on casting numbers 6.0s would run cupped shaped pistons, and 4.8 would need domes to make up the diff in comp because of bore size. 5.7 heads on a 6.0 will give u a bump in compression. There chambers are set up for a smaller piston than the 6.0s. Call trick flow n ask bout a set of heads that are 9.1:1 compression, and they will ask wat ur putting them on. Combustion chamber and pistion, size and type play big rolls in compression. So lol what motor did ur heads come off of?

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you got your shit twisted

Went to sleep, woke up, read this and lmao. Yes yes yes, bootlife, you are 100%correct! Continue to look for 243 heads that were only in a 6.0. -_- some people......
Think of it this way. If they had different bowl sizes, then WTF would they have all the other head casting numbers??????? There'd be no point. 243 cast is a 243 cast no matter what they put it on!!!!

243s on a 4.8 equal 9.1 compression ratio.

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Originally Posted by RS/SS 4.8

243s on a 4.8 equal 9.1 compression ratio.

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8.8 going by gm listing for 2010 4.8

I knew it the one I looked up was 9.1 for a 09 but I had posted 8.8 then changed it to 9.1. Free bump. GLWS

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Originally Posted by ecld_07

Are you sure. Surely a larger cumbustion chamber wouldn't drop compression..... Bump for a good seller and thread crappers

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Larger combustion chambers will lower compression if the heads they are replacing had smaller chambers, example an 06 lq9 and an 06 ls2 use the same pistons, the lq9 uses a 71cc chamber and the ls2 uses a 64.5cc ( even tho GM displays it at 64cc ) the lq9 registers a Compression Ratio of 10.1:1, the ls2 with its smaller combustion chamber with the SAME piston it will yield an 11:1 compression ratio. This example was given based off of identical bore x stroke combos based off of a 4" inch bore using identical pistons..... Hope this helps bump :)

But guys, true 6.0 243's on a "cupped" piston 5.3 would be approximately 12.687 CR, but if they came off a 5.7 and were put on a 4.8 with "domes" it would have 7.569 CR. Bump for a stinky okie. Btw, I wish I could afford them lol, but Im broke as always

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Originally Posted by o2camaross

But guys, true 6.0 243's on a "cupped" piston 5.3 would be approximately 12.687 CR, but if they came off a 5.7 and were put on a 4.8 with "domes" it would have 7.569 CR. Bump for a stinky okie. Btw, I wish I could afford them lol, but Im broke as always

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you seriously cant be serious with that math

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Originally Posted by MrHorsepowerLSx

Larger combustion chambers will lower compression if the heads they are replacing had smaller chambers, example an 06 lq9 and an 06 ls2 use the same pistons, the lq9 uses a 71cc chamber and the ls2 uses a 64.5cc ( even tho GM displays it at 64cc ) the lq9 registers a Compression Ratio of 10.1:1, the ls2 with its smaller combustion chamber with the SAME piston it will yield an 11:1 compression ratio. This example was given based off of identical bore x stroke combos based off of a 4" inch bore using identical pistons..... Hope this helps bump :)

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Was a joke... Lol

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Originally Posted by George C

you seriously cant be serious with that math

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Come on George. Twas a joke my friend

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Originally Posted by o2camaross

Come on George. Twas a joke my friend

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lol @ you guys... SOMEONE BUY THESE THINGS! $400 plus shipping!

SOLD! Close thread...

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Originally Posted by MrHorsepowerLSx

Larger combustion chambers will lower compression if the heads they are replacing had smaller chambers, example an 06 lq9 and an 06 ls2 use the same pistons, the lq9 uses a 71cc chamber and the ls2 uses a 64.5cc ( even tho GM displays it at 64cc ) the lq9 registers a Compression Ratio of 10.1:1, the ls2 with its smaller combustion chamber with the SAME piston it will yield an 11:1 compression ratio. This example was given based off of identical bore x stroke combos based off of a 4" inch bore using identical pistons..... Hope this helps bump :)

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Thanks!!!! Least somebody knows wats going on

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Originally Posted by bootlife

Thanks!!!! Least somebody knows wats going on

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I think you are trying to argue something completely different. All stock 243s are the same no matter what motor they come from minus the valve thing. Different motors will net different cr according to a lot of factors that have little to do with the heads and everything to do with pistons, stroke, etc. Not all 5.3s are created equally, but all 243s basically are.

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Originally Posted by bootlife

Thanks!!!! Least somebody knows wats going on

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Let me go ahead and reiterate something I've said about you multiple times... you're literally the dumbest guy on this forum at this point. Please, do us all a favor and don't speak.

I don't know about the 243s, but a lot of heads have diff combustion chambers. My brother in law bought a 350 that was a reman n it had 305 heads on it, and cupped pistons so comp would be right, needles to say a 350 head swap was not going to work for him. I was looking in to doing heads on my 5.3 last year and the heads I was looking at had the wrong combustion chamber, they told me I could have them milled but that causes issues in its own way.

My heads are milled. Zero issues.

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Originally Posted by bootlife

I don't know about the 243s, but a lot of heads have diff combustion chambers. My brother in law bought a 350 that was a reman n it had 305 heads on it, and cupped pistons so comp would be right, needles to say a 350 head swap was not going to work for him. I was looking in to doing heads on my 5.3 last year and the heads I was looking at had the wrong combustion chamber, they told me I could have them milled but that causes issues in its own way.

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I very well might be the most patient person on this site when it comes to ignorance, newb questions, and misunderstandings, but I'm just going to leave these here.
http://i1142.photobucket.com/albums/...3e70558210.jpg
http://i1142.photobucket.com/albums/...e8df9a56da.jpg
http://i1142.photobucket.com/albums/...108e3c0e6f.jpg

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Originally Posted by Frenchy

My heads are milled. Zero issues.

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Hmmmmm, mine too. Took .030 off a set of 241's and my shiz runs pretty darn good.

I had to mill my 6.0 243's .030 so they matched 5.3 243's.